Wednesday, January 28, 2009

Intel's RF energy harvester

Intel set up a TV antenna on a balcony with line of sight to the KING-TV tower 4.1 km away. The TV station broadcasts on channel 48 between 674 and 680 MHz with an effective radiation power (ERP) of 960 Kw. The TV antenna used was a UHF log periodic with 5 dBi gain connected to a 4 stage charge pump power harvesting circuit of the same design as that found in an RFID tag. Across an 8 KOhm load the team measured 0.7V, corresponding to 60 microwatts of power harvested. That was enough to drive a thermometer/hygrometer and its LCD display, which is normally powered, by a 1.5 volt AAA battery.

Source

Technical papers here

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